The invention relates generally to call centers or other call processing systems in which voice calls, e-mails, faxes, voice messages, text messages, Internet service requests or other types of communications are distributed among a number of service agents for handling, and more particularly to call centers which include multiple geographically-distributed work sites.
Call centers distribute calls and other types of communications or work items to available service agents in accordance with various predetermined criteria. A given call center may be implemented in a geographically distributed manner, e.g., as a combination of multiple distributed call center sites at different locations. Such an arrangement is commonly referred to as a multi-site call center or more generally a multi-site call processing system. In multi-site systems of this type, a centralized load balancing process is typically utilized in order to distribute communications among the various sites for processing.
The purpose of the load balancing process is generally to create as close to a single-queue operation as possible within the multi-site system. More specifically, the load balancing process is designed to ensure that all callers are served with as short a wait time as possible, and to keep agents working uniformly across the multiple sites. Callers arriving at about the same time needing the same type of service from agents should thus have about the same amount of wait time regardless of which site serves each caller, and agents at one site should not be idle or under-worked while agents at another site are overworked.
Conventional load balancing processes generally involve comparison of raw data such as Average Speed of Answer (ASA) for each call. More specifically, the conventional processes look at ASA by interval for each agent skill and for each of the sites supporting the skill. In general, the ASAs should be nearly identical and rise and fall together, showing that those who called at about the same time had about the same wait, regardless of which site served the call. Other conventional load balancing processes compare other types of raw data, such as agent occupancy, across the multiple sites.
A significant problem with these and other conventional approaches to load balancing is that comparisons of raw data are often limited in their usefulness because the resulting numbers can be difficult to use in making performance judgments. This is particularly true when comparing one balanced system to another. For example, it may be difficult in such situations to determine whether the performance of load balancing which results in ASAs of 45 seconds, 55 seconds and 65 seconds is better or worse than the performance of load balancing which results in ASAs of 450 seconds, 485 seconds and 500 seconds. Although the callers experiencing the former set of ASAs certainly waited significantly less time, it is not directly apparent which set of ASAs represents the better load balancing.
A need therefore exists for improved data analysis techniques for use in conjunction with load balancing in multi-site call processing systems.
The invention in an illustrative embodiment provides methods and apparatus for characterization, comparison and adjustment of load balancing processes in multi-site call processing systems.
In accordance with the invention, a multi-site call processing system includes multiple distributed call center sites, and utilizes a load balancing process to distribute calls among the sites for handling by agents. The system generates a multi-site performance score characterizing the performance of the load balancing process. Adjustments may be made in the load balancing process, such as selection of one type of load balancing over another for use at a particular time, based at least in part on the multi-site performance score. The multi-site performance score may be determined using single-site performance measures such as Average Speed of Answer (ASA) and agent occupancy generated across multiple time intervals. The multi-site performance score as generated for a given interval may be, e.g., a ratio of the maximum and minimum values of single-site performance measures for that interval. As another example, the multi-site performance score may be in the form of a standard deviation of a set of normalized scores generated for the multiple sites across the specified time intervals. Each of the normalized scores in the set of normalized scores may be generated by taking a particular single-site performance measure for a corresponding site and dividing it by a site average computed across all of the sites. Graphical representations of the multi-site performance scores may be generated in order to facilitate data analysis.
In accordance with another aspect of the invention, filtering operations may be applied to the data for one or more selected intervals in order to further improve the ability of the performance measure to distinguish relevant variations in the load balancing process. For example, such a filtering operation may be applied to normalized scores for a given one of the time intervals if a particular measure used to generate the normalized scores for each of the multiple sites is below a designated threshold in that interval. The filtering may be configured to remove normalized scores for the given interval from a computation of the multi-site performance score. Alternatively, the filtering may involve setting each of at least a subset of the normalized scores for the given interval to a particular value prior to computation of the multi-site performance score. Other types of filtering may also be used.